1. Field of Invention
The present invention relates to a fuel cell which undergoes reaction of various kinds of reactive gases supplied into the respective electrodes to generate electricity and a process for the production thereof.
2. Description of Related Art
Heretofore, there have been fuel cells including an ion-permeable electrolyte provided interposed between porous electron-permeable electrodes. Among these fuel cells are those which use hydrogen, natural gas, alcohol or the like as a fuel to generate electricity. Among these fuel cells, the fuel cell which uses, for example, hydrogen as a fuel receives a first reactive gas containing hydrogen in one electrode and a second reactive gas containing oxygen in the other electrode to generate electricity by the reaction of the hydrogen contained in the first reactive gas with the oxygen contained in the second reactive gas.
The substrate of the fuel cell has a gas flow path formed therein for supplying a reactive gas. The reactive gas is supplied through the gas flow path. Accordingly, in order to prevent the material constituting the electrode, such as particulate carbon, from entering in the gas flow path and clogging the space for the flow of the reactive gas, particulate carbon having a greater particle diameter than that of particulate carbon constituting the electrode is disposed in the gas flow path.
A microfuel cell which can be incorporated in cellular phone, and the like is now under research and development. For the production of such a microfuel cell, MEMS (Micro Electro Mechanical System) based on micromachining technology used in semiconductor processing, etc. is used to form a fine gas flow path. Referring to the use of MEMS, a fine gas flow path is formed on the surface of a substrate, such as silicone. An electrically-conductive layer and an electrode made of carbon or the like are then formed on the substrate having a gas flow path formed thereon. A previously formed electrolyte membrane is disposed interposed between two sheets of these substrates having an electrode and other layers formed thereon and then contact-bonded thereto to produce a fuel cell (see, for example, Sang-Joon J Lee, Suk Won Cha, Amy Ching-Chien, O'Hayre and Fritz B. PrinzFactrical, Design Study of Miniature Fuel Cells with Micromachined Silicon Flow Structures, The 200th Meeting of The Electrochemical Society, Abstract No. 452 (2001) and Amy Ching-Chien, Suk Won Cha, Sang-Joon J Lee, O'Hayre and Fritz B. PrinzPlaner, Interconnection of Multiple Polymer Electrolyte Membrane Micro Fabrication, The 200th Meeting of The Electrochemical Society, Abstract No. 453 (2001)).